1. Field of the Invention
The invention relates to stents and more particularly to a method of implanting an aortic stent.
2. Description of Related Art
A conventional aortic stent is shown in FIG. 7. And the main stent 7 is disposed from ascending aorta (AA). As shown in FIG. 7, the length of ascending aorta is short and does not have a sufficient space. Also, there is no securing device for the main stent 7 and the main stent 7 may be movable. More importantly, when the main stent 7 is secured, it also takes time to secure the branch grafts into branchiocephalic artery (BA), common carotid artery (CCA), left subclavian artery (LSCA) and descending aorta (DA) before the blood can flow thereto. Meanwhile, if the main stent 7 moves when the blood flows therethrough, it may block the blood flow to either BA, CCA, LSCA or DA. Moreover, if it takes too long to dispose a plurality of stents 71,72,73,74, a permanent damage may be caused to the brain because of insufficient blood flow.
Furthermore, the way the main stent 7 is disposed in the ascending aorta cannot be achieved by a minimally invasive surgery. Actually, if utilizing the way to dispose the main stent 7, the doctor has to conduct a surgery to open up part of the sternum. Also, the way may cause Iatrogenic aortic dissection as shown in FIG. 8.
There are three portions in a cross section of a blood vessel from inside to outside: Tunica intima 6, Tunica media 5 and Tunica adventitia 4. When there is a cut on the inner wall of the blood vessel, the blood stream with high pressure is pouring into the cut and tearing the tunica intima 6 out of other layers of arterial wall, which can be a fatal complication. The blood flow could bi-directional intima flap and caused type A dissection. More seriously, the orifice of coronary artery that located at aortic rout would be obstruction by hematoma compression and leading fatal myocardial infarction.
Moreover, it is difficult to dispose the stent 74 as U shape as shown in FIG. 7.
Thus, the need for improvement still exists.